Influence of neighbouring tube expansion on the residual stress of tubesheet with single-row holes

Abstract

Abstract 1 The expansion joint is a commonly used method of connection tube and tubesheet in the pressure vessel industry. This paper established the rationality of the numerical simulation method by comparing with the analytical model. On this basis, the effect of neighbouring tube expansion on the residual stress of tubesheet with single-row holes was investigated, as well as the effect of the cyclic joint temperature changes on the tubesheet stress amplitude. Finally, preliminary work was conducted to determine the fatigue life of pressure vessels considering expansion factors. The results indicated that as the model was extended from one hole to 10 holes, the maximum and average stresses of each hole increased gradually and stabilized at a limit value when the model reached 10 holes, and the maximum and average stress in the expanded cases were approximately 13% and 10% higher than those in the unexpanded case, respectively. Residual stress results will lead to the change of stress distribution and the increase of stress amplitude, and then affect the fatigue life of the pressure vessel equipment. •Multilinear kinematic hardening model are used to exhibits the Bauschinger effect. •Numerical simulation method is validated by the analytical model. •Expansion process has a great influence on the stress level of the tube holes. •Residual stress leads to a significant change of tubesheet stress distribution. •Residual stress increases the stress amplitude and affects fatigue life.